METHODS: The transcriptomes were sequenced on the Illumina HiSeq platform, assembled and followed by transcript clustering and annotations for gene expression and function. Pairwise or multiple sequence alignments were conducted on the toxin genes expressed. Substitution rates were studied for the major toxins co-expressed in NK-M and NK-T.
RESULTS AND DISCUSSION: The toxin transcripts showed high redundancy (41-82% of the total mRNA expression) and comprised 23 gene families expressed in NK-M and NK-T, respectively (22 gene families were co-expressed). Among the venom genes, three-finger toxins (3FTxs) predominated in the expression, with multiple sequences noted. Comparative analysis and selection study revealed that 3FTxs are genetically conserved between the geographical specimens whilst demonstrating distinct differential expression patterns, implying gene up-regulation for selected principal toxins, or alternatively, enhanced transcript degradation or lack of transcription of certain traits. One of the striking features that elucidates the inter-geographical venom variation is the up-regulation of α-neurotoxins (constitutes ∼80.0% of toxin's fragments per kilobase of exon model per million mapped reads (FPKM)), particularly the long-chain α-elapitoxin-Nk2a (48.3%) in NK-T but only 1.7% was noted in NK-M. Instead, short neurotoxin isoforms were up-regulated in NK-M (46.4%). Another distinct transcriptional pattern observed is the exclusively and abundantly expressed cytotoxin CTX-3 in NK-T. The findings suggested correlation with the geographical variation in proteome and toxicity of the venom, and support the call for optimising antivenom production and use in the region. Besides, the current study uncovered full and partial sequences of numerous toxin genes from N. kaouthia which have not been reported hitherto; these include N. kaouthia-specific l-amino acid oxidase (LAAO), snake venom serine protease (SVSP), cystatin, acetylcholinesterase (AChE), hyaluronidase (HYA), waprin, phospholipase B (PLB), aminopeptidase (AP), neprilysin, etc. Taken together, the findings further enrich the snake toxin database and provide deeper insights into the genetic diversity of cobra venom toxins.
MATERIALS AND METHODS: In this retrospective review, data collected during 2006-2015 from the medical charts of patients with evidence of infection, caused by any Salmonella serogroup or clinical form, were examined. We aimed to assess the clinical manifestations, antibiotic susceptibility, and antibiotic use in children with Salmonella gastroenteritis over the ten years' period.
RESULTS: A total of 419 patients had non-typhoidal Salmonella infection. Four-hundred (95.5%) patients were diagnosed with acute gastroenteritis, which was common in children aged <12 months (72.3%). The clinical features of patients with gastroenteritis included fever (74.5%), diarrhoea with bloody mucus (60.5%), watery diarrhoea (39.5%), and vomiting (19.8%). Serogroup B was most commonly detected in the stool specimens. The susceptibility of non-typhoidal Salmonella to ampicillin, norfloxacin, and co-trimoxazole was 36.3%, 98.0%, and 80.5%, respectively. Serogroup B was the most resistant strain, which was sensitive to ampicillin in only 21.6% of specimens, while it showed high susceptibility to norfloxacin and co-trimoxazole (98.1 and 84.0%, respectively). Third-generation cephalosporin and fluoroquinolone were most commonly prescribed.
CONCLUSIONS: Acute gastroenteritis is the most common form of Salmonella infection. Gastroenteritis caused by serogroup B is still the most common infection, which mostly occurs among infants under one year of age. The majority of stool specimens were still susceptible to antimicrobial agents, especially fluoroquinolone and cotrimoxazole; however, there was an overuse of antibiotics without proper indications.